Mars rover's peek at rock turns up a curiosity

The first rock nuzzled by NASA's Mars Curiosity rover is turning out to be a bit more unusual than scientists thought it would be.

Curiosity used its robot arm to touch at a football-sized pyramid-shaped rock for the first time two weeks ago. It also shot the rock dozens of times with a laser.

The results surprised scientists. They said Thursday that it is not like other rocks seen on Mars. It has more sodium and potassium.

Scientist Edward Stolper (STOHL'-pur) said the rock is more like rare volcanic rocks seen on Earth in places like Hawaii. Those rocks are formed under high pressure, deep underground and once contained water.